The official marathon distance of just over 42 kilometres is more than many of us can imagine dragging our bodies around, but for those at the front of the pack, the distance just isn’t enough of a challenge. Add extreme weather or altitude, or double the distance, and you’ll flush out those die-hards who just can’t resist pushing themselves further.

While many races may lay claim to the title of “world’s hardest”, the Barkley 100 Mile run seems to be most often described as such. While the course has changed a number of times, the basic construction remains a series of 32km loops that are run in the inhospitable terrain of the Frozen Head State Park in Tennessee in the United States. Including 16 500m of accumulated vertical climb, the race is limited to 35 runners who have to write a motivational essay entitled “Why I should be allowed to run in the Barkley”. Competitors have to tear pages out of strategically placed books to prove that they have done the complete circuit each time.

The world’s highest marathon is 42kms of mostly downhill running, starting near the Everest base camp at a level of 5 184m above sea level. Because of the altitude, participants have to spend 26 days getting used to the conditions amongst the foothills of the Himalayas. The course may include ice and snow and the terrain is rough underfoot – definitely not a challenge to embrace on the spur of the moment.

Every December, around 1 000 cold weather running fans brave the Siberian winter in what is often billed as the coldest race in the world. With temperatures reaching lows well below zero, only the strong will complete the course. The marathon was disrupted by the weather only once, on its 10th anniversary in 2001, when the temperature dropped to a crushing minus 39 deg C. In that year only 13 participants ran the full 21.1kms.

With temperatures that can get up to 55 deg C and a distance of 217kms, the 90 or so participants in the Badwater Ultramarathon are sure to work up a significant sweat. The race takes place from Death Valley to Mount Whitney in California, and demands a high level of heat endurance and fitness from runners.

The Sahara desert is the location for what many call the toughest race on earth. Run over 7 days, the Marathon des Sables covers 249km of sand and more sand. Simply finishing is an achievement in itself, as the elements threaten to overwhelm the body’s ability to adapt to extremes.

A few tips from the organisers of The Marathon Des Sables for the next time you decide to run across the Sahara.

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